The present invention relates generally to a method and apparatus for cutting sheets of material such as foam adhesive material.
Often, composite components such as those used in gas turbine engines are made by assembling sub-components such as sheets of carbon reinforced resins and/or more complex structures in predetermined orientations. Sheets of adhesive material are applied to the sub-components and activated to form the composite components. Frequently, the sheets of adhesive material are a foam or film epoxy material having paper backing covering each face prior to use.
Conventionally, a knife and a straight edge are used to cut the sheets of adhesive. However, as the sheets are cut, the technician simultaneously must hold the straight edge in place on the sheet of material, hold the knife against the straight edge and press the knife against the sheet of adhesive with sufficient force to cut the adhesive. If the knife becomes spaced from the straight edge or the straight edge moves, the cut will not be straight. Further, this procedure sometimes produces slivers of the adhesive, slivers of the paper backing, and/or slivers of the straight edge. If the slivers are not found and removed, they can become embedded in the components. In addition, the knife must be periodically sharpened or replaced thereby adding cost to the components.
Among the several features of the present invention may be noted the provision of an apparatus for cutting a sheet of material along a preselected line. The apparatus includes a table having an upper surface sized and shaped for receiving the sheet of material. In addition, the apparatus includes a wire positionable adjacent the upper surface of the table and generally vertically below the preselected line on the sheet of material when the sheet of material is received by the upper surface of the table. Further, the apparatus includes an elongate guide positionable above the sheet of material when the sheet is received by the upper surface of the table for holding the sheet of material in position with respect to the wire and the upper surface of the table. The apparatus also includes a device engageable with the wire for pulling the wire upward through the sheet of material to cut the sheet of material along the preselected line.
In another aspect, apparatus of the present invention includes a table and an elongate guide positionable above the sheet of material when the sheet is received by the table. The guide has a track extending longitudinally along the guide. Further, the guide has two inward facing edges spaced by a gap having a generally constant width positioned generally vertically above the preselected line on the sheet of material when the guide is positioned above the sheet of material and the sheet is received by the table. In addition, the apparatus includes a wire positionable adjacent the upper surface of the table and below the sheet of material when the sheet of material is received by the upper surface of the table. The wire is positioned laterally between the edges and vertically below the gap of the guide when the guide is positioned above the sheet of material. The apparatus also includes a shuttle moveably engaging the guide track for pulling the wire upward through the sheet of material and through the gap in the guide to cut the sheet of material along the preselected line.
Moreover, the present invention includes a method of cutting a sheet of material. The method includes positioning an elongate guide adjacent a first face of a sheet of material and positioning a wire adjacent a second face of the sheet of material opposite the first face. Further the method includes the step of pulling the wire through the sheet of material and through the gap between the spaced edges of the elongate guide to cut the sheet of material.
Other features of the present invention will be in part apparent and in part pointed out hereinafter.